H1B to L1A after working outside USA for 1 year

I am currently on H1B (7th year) with my I140 approved in EB2, PD in 2021 with employer A. If I moved to Canada working for employer B for 1 year in managerial/executive role, Can I return on L1A for employer B?
will I be eligible for EB1c?
Could I briefly (few days at a time) travel to the US on H4 during my employment in Canada?
I am aware that those days won’t count towards 1 year of employment with employer B.

USCIS L1 One Year Foreign Employment Policy - USA USCIS L1 One Year Foreign Employment Policy - USA